100 PRACTICAL TROUT CULTURE. 



gill-covers have not yet appeared, and four lines on 

 either side of the throat represent the future gills. 

 The motions of the little creature are slow ; borne 

 down by the weight of his huge appendage, com- 

 monly known as the umbilical vessicle, but more 

 properly as the yolk sac, he seeks quiet and 

 hides himself among the gravel. Strange as the 

 sac may appear to others, to him it is a matter 

 of vital importance. It is the food upon which he 

 is nourished during the first six weeks of his ex- 

 istence. He requires no other, will accept of 

 none ; but hides himself from view and only de- 

 sires to be severely let alone. 



But the labors of the fish culturist know no 

 rest. Many at this stage may die, and some surely 

 will. Daily must the nursery be thoroughly ex- 

 amined and all dead removed? The bulb syringe 

 here again comes into play. To facilitate the ex- 

 amination of the troughs, a watch-maker's mag- 

 nifying glass, firmly attached to the eye by a 

 broad india-rubber band passing around the fore- 

 head, will be found of great service. Care and at- 

 tention is now absolutely necessary ; neglect will 

 certainly be followed by heavy loss the dreaded 

 byssus forming upon all dead animal matter and 

 filling the waters with its almost imperceptible 

 fibers. To aid its feeble respiration, the pectoral 

 fins of the young fish are in constant, rapid mo- 



